1. Field of the Invention
The present invention relates to a circuit for driving an inductive load such as a coil or an inductor.
2. Description of the Related Art
In a conventional control circuit for a vehicular generator, the output voltage thereof is regulated by on-off control of the current supplied to the field coil. The field coil has a large inductance and, therefore, is a kind of an inductive load. In order to supply back-flow current to the field coil, a back-flow element such as a flywheel diode is connected to the field coil.
However, such a flywheel diode has a considerably large forward voltage drop and generates considerable heat, and the size of the diode must be increased in order to reduce the current density. It is also necessary to eliminate accumulation of the carriers near the pn junction. For this purpose, additional current is supplied to recombine the carriers when the field coil is energized. This causes switching noises and increases the response time of the switching operation.